Current structural and compositional studies of brain synaptic membranes suffer from the lack of sufficiently pure fractions enriched in synaptic domains. we propose to develop "affinity" based methods for isolation of membranes enriched in synaptic domains. These fractions will be analyzed for protein, lipid and carbohydrate components with special emphasis on neurotransmitter receptors, enzymes and certain fibrous proteins. The fractions will be morphologically characterized using transmission electron microscopy and cytochemical staining procedures.